FERGUSON, Mo. - Police began using tear gas to disperse crowds early Monday morning in suburban St. Louis after multiple stores were vandalized and looted Sunday night. Crowds became unruly at a vigil for an unarmed black man who was shot and killed by police.

People smashed car windows and carried away armloads of looted goods from stores in Ferguson and Dellwood after the vigil for Michael Brown, 18, who died Saturday after being shot multiple times by a Ferguson police officer.

Among other businesses, a QuikTrip convenience store and a nearby liquor store were damaged and looted. A fire was set behind the liquor store, according to reporters on the scene. There were multiple reports of gunfire.

Alderman Antonio French of the 21st Ward in St. Louis, posted several Vine videos on Twitter Sunday night showing looters smashing windows and carrying off goods. A little after midnight he tweeted that the looting had spread to neighboring Dellwood.

Ferguson police called in an extra 60 officers as well as police from all surrounding jurisdictions. St. Louis city police were assisting by answering calls in St. Louis County, and a St. Louis SWAT team was staging.

Around 8 p.m. Central Time, people began gathering at the scene where the shooting occurred. One group of young men broke off to spray paint "R.I.P. Michael" on the street, and others placed candles, flowers and a teddy bear at the exact location where Brown was killed.

Earlier in the day, shouts of "No justice, no peace" and "We want answers" nearly drowned out a news conference as St. Louis County Police Chief Jon Belmar detailed the shooting.

It began with an altercation involving two men and the officer around noon Saturday, Belmar said. One of the men pushed the officer into his patrol car, there was a scuffle inside the car over the officer's gun, and the officer fired one shot inside the cruiser.

Seconds later, outside the cruiser, he fired several more shots and 18-year-old Michael Brown lay dead.

Brown was unarmed, and all the shell casings found on the ground were from the officer's gun, Belmar said.

Brown's mother, Lesley McSpadden, said Sunday she doesn't understand why police didn't subdue her son with a club or Taser. She said police have not explained why the officer confronted him.

"I would like to see him fired," McSpadden said. "I would like to see him go to jail with the death penalty."

"My son just turned 18 and graduated from high school, and he don't bother nobody," she said Saturday night. She said he was looking forward to starting at Vatterott College next week.

"They told me how many times my son was shot. Eight," McSpadden said.

She said he was visiting his grandmother, who lives in the complex in a predominantly black suburb of the city, and was returning from the store.

The St. Louis County NAACP has called for an FBI investigation and Belmar has contacted the FBI.

John Gaskin, with the St. Louis County NAACP, alluded to the racially charged 2012 shooting of 17-year-old Trayvon Martin by George Zimmerman, a neighborhood watch organizer who was subsequently acquitted of murder, and the death of a New York man from a police chokehold after he was confronted on suspicion of selling individual cigarettes.

"With the recent events of a young man killed by the police in New York City and with Trayvon Martin and with all the other African-American young men that have been killed by police officers â?¦ this is a dire concern to the NAACP, especially our local organization," Gaskin said.

Ferguson Police Chief Thomas Jackson said police are in contact with the second person who was involved in the altercation. Authorities aren't sure if the second person was unarmed, Jackson said.

Belmar said that when the investigation is complete, the findings will be turned over to the St. Louis County Prosecuting Attorney's Office.

The identity of the officer who shot Brown has not been disclosed by police. He has been with the Ferguson Police Department for about six years, Belmar said. He was put on paid administrative leave and was being interviewed by investigators. Jackson told Belmar the officer will undergo two psychological evaluations if it is determined he can return to active duty.

The St. Louis County Police Department said Ferguson police cars do not have dash cameras and there is no surveillance video at the apartment complex where the shooting occurred.

St. Louis Mayor Francis Slay tweeted Sunday saying he stands with County Executive Charlie Dooley in his call "for a full and open inquiry into yesterday's shooting in Ferguson."

Outside the Ferguson Police Department's headquarters Sunday morning protesters raised their hands in the air and chanted, "Don't shoot."

On Saturday, witnesses said Brown had raised his hands in the air before he was shot, but that was not confirmed by Belmar.

Protesters called for 10,000 people to join them at 10 a.m. Monday at the Ferguson Police Department. The crowd marched through the streets Sunday morning and afternoon.

The Rev. Al Sharpton says the shooting death of Brown is "very disturbing," and the civil-rights leader is planning a visit to Ferguson to make that known.

Sharpton tells The Associated Press that he's spoken with a grandfather of Michael Brown and plans to meet with the family in person Monday night or Tuesday in Ferguson.